Its a lot more convenient using cards rather than cash , you can buy what you need without the chore of having to make sure that you have cash in your pocket or looking if there is an ATM close buy .
Like, seeing something in a shop , then walking around trying to find an ATM , then making a withdrawal and taking the cash back to the shop to buy the item and they give you change back .
Much easier just to swipe you card there and then at the check-out, rather than the chore of paying cash